1. Field of the Invention
This invention relates to a display device comprising a light-emitting display portion which utilizes biochemical luminous reaction in which enzymes or the like participate and perform switching by controlling electrochemically said luminous reaction.
2. Related Background Art
Heretofore, as artificial display devices utilizing electrical energy, there have been known, for example, those having a light-emitting display portion comprising a luminescent layer containing a material having the EL (electroluminescence) function such as ZnS, etc., between a pair of electrodes or those using LED (light emitting diode) for the light-emitting display portion.
In contrast with such artificial light-emitting systems, the system of bioluminescence as seen in bacteria or glowfly takes out the difference in chemical potential directly as light energy and converts chemical energy directly to light energy, and thus bioluminescence is known to exhibit extremely high luminescence quantum efficiency, for example, 0.88 in the case of luminescence quantum efficiency of a glowfly, without wasting effective energy in a form of heat, etc.
As a report describing generally a bioluminescence system as mentioned above, "Photochemistry and Photobiology, Vol. 37, No. 6, pp. 709-715, 1983" is mentioned for the purpose of reference.
Thus, various functions performed in a living body surpass functions of artificial systems in many cases, and this is considered to result largely from the characteristics of biochemical reactions such as extremely high conversion of various chemical reactions or very high specificity of the reaction in living bodies.
Accordingly, bioreactors or biosensors are attracting attention and comprehensively studied, and these devices will soon be commercialized in consequence of development of immobilization techniques for enzymes or microorganisms.
However, under the present situation, for practical utilization of various instruments utilizing biological reactions as mentioned above, the method of controlling and switching biochemical reaction has not yet been completely established. Particularly, in a device utilizing a bioluminous reaction, no suitable method has been known yet for controlling and switching biochemical reaction concerning luminescence.